test: add --add-dir flag for temp directory access

Claude needs explicit permission to access the temp test directory.
Added --add-dir flag to grant access to the test project.

tests/claude-code/test-subagent-driven-development-integration.sh

@@ -149,7 +149,7 @@ Begin now. Execute the plan."
 
 echo "Running Claude (output will be shown below and saved to $OUTPUT_FILE)..."
 echo "================================================================================"
-cd "$SCRIPT_DIR/../.." && timeout 1800 claude -p "$PROMPT" --allowed-tools=all 2>&1 | tee "$OUTPUT_FILE" || {
+cd "$SCRIPT_DIR/../.." && timeout 1800 claude -p "$PROMPT" --allowed-tools=all --add-dir "$TEST_PROJECT" 2>&1 | tee "$OUTPUT_FILE" || {
     echo ""
     echo "================================================================================"
     echo "EXECUTION FAILED (exit code: $?)"